IN the earlier ages of mankind, when the knowledge of Nature was small, and confined to priests and sages, their explanations were received with a simple childlike faith by the people, who cared not, or, if they cared, dared not to question or inquire further. These explanations were, for the most part, mere fanciful and arbitrary guesses, founded, not upon ascertained facts, but on the simplest conceptions arising from the consciousness of some supreme power or powers, which governed the universe, and accommodated to the religious theories of the time. All the mysteries of Nature were solved by the supposition of innumerable supernatural agents, according to whose caprice mankind were injured or benefited, punished or rewarded. Medicine was consequently intimately associated with religion; among the more barbarous nations, the priest and the medicine-man were identical; and, among the more civilized, the recognized practice of it was confined to the sacerdotal orders until the thirteenth or fourteenth century. Neither the priests nor the people of the superstitious age could understand invariable laws.

If a solar eclipse took place, a dragon was supposed to have swallowed up the sun; if an earthquake occurred, or a volcano burst forth, some subterraneous demon was presumed to be at work. When a pestilence raged, the invisible arrows of an offended deity struck down the victims. A man who lost speech or hearing had a dumb devil or a deaf one. We see the same condition of mind exemplified now in the fetichism of barbarous nations, and the belief in charms and sorcery which still obtains among the vulgar, even in this country. But at no period was it more conspicuous than in the middle ages, when the belief in magic and witchcraft gave rise to the terrible atrocities which were perpetrated in the punishment of those who were supposed to plot evil against their fellows by direct compact with and assistance from the devil. If a man suffered from pain in the region of the heart, or in the head, a witch inflicted these tortures by secretly sticking pins into the corresponding portion of a wax image representing the sufferer, and thousands of unfortunates were burnt for causing disease and death by their unholy incantations. The dancing mania, which arose in Flanders and Germany during the fourteenth century, was regarded as a display of satanic power, and the popular reason assigned was that the boots with pointed toes, which had been lately introduced, were peculiarly offensive to the Almighty!

With the belief in witchcraft and sorcery, prevailed also the belief in astrology, and that so universally, even among the more highly-educated, that, although occasionally some daring minds raised their voices against the delusion, the storm of obloquy and contempt which was showered on them served to show the strength and popularity of the superstition. The heavens were divided, by the most educated men of the time, into houses of life and of death, of riches, marriage, or religion, and the particular planet which chanced to be in any one house at the time, was denominated the lord of the house, in power over the destinies of mankind, unless a greater than he reigned elsewhere.

While this firm belief in magic, and this disposition to refer all diseases to the direct interposition of supernatural agencies, continued to prevail, the science of medicine necessarily remained almost stationary, or rather could hardly come into existence. Few ever thought of trying to find out how sorcerers, demons, and planets did their work—and the Church terribly punished all who dared to attempt the investigation. As magic—a mysterious power which man could not understand, but thoroughly believed in—caused diseases, so a kind of magic was trusted to cure them. The efficacy of relics and charms was universally acknowledged. The efforts of physicians were directed to the invention of nostrums and counter charms—not to the investigation of the causes of disease, the careful observation of their phenomena, or the mode of action of the remedies prescribed for them. Galen had, indeed, made important discoveries in anatomy in the second century, and Mondino and others had added to them; but their knowledge was rude and imperfect, and their deductions vitiated by the most absurd physiological dogmas. When they had discovered a few broad and simple facts in anatomy, they rested from their labors, well content; and founded theories, supported by unfounded assumptions, but which became articles of faith, received without question by their successors in the study. Galen, for example, assumed that the arteries carried the purest blood from the left ventricle of the heart, to the higher and more refined organs, the brain and lungs; while the veins conveyed that of inferior quality from the right ventricle to the grosser organs, the liver and spleen. He chose, moreover, to affirm that the venous blood was not fit for its office, unless some portion of the essence or spirit, and of the arterial blood contained in the left ventricle, were infused into it. Now, these two chambers of the heart, each containing the different quality of blood above mentioned, are separated by a partition, through which there is no aperture whatever. Holes of communication were, however, required by Galen to support his theory, and, therefore, in the true spirit of the time, holes were accordingly seen by him. He squared his facts to suit his theory. And, stranger still, although the heart was frequently examined afterward, so paramount was the authority of Galen, that these imaginary holes were seen by a succession of anatomists for fourteen hundred years, until, at last, Vesalius dared to declare that he could not find them.

This profound reverence for authority, this belief in supernatural agencies, and this stagnation of true science, was the condition which prevailed at the beginning of the sixteenth century. But education gradually spread, and at this time thinkers arose, who, dissatisfied with mere assumptions, or the baseless dicta of previous authorities, commenced working at the rudiments of the science which had hitherto rested on such imperfect foundations.

Protestantism broke forth, marking the commencement of the age of free inquiry, the spirit of which had so often been quenched in blood to burst forth again irrepressibly, and henceforth to continue and spread abroad with little interruption. The Italians—and more especially the republican Venetians—appear to have been peculiarly free from the prejudice against the dissection of human bodies which generally prevailed; the study of anatomy was warmly encouraged at Padua and Bologna; and, owing to this liberal spirit, Mondino, in the fourteenth century, was enabled to demonstrate human anatomy by actual dissection. But he was so trammelled by tradition and the authority of Galen, that he perpetuated numberless errors, which would have been patent enough to an unprejudiced mind. So powerful were these influences, even two hundred years later, that Berenger, who boasted of having dissected one hundred subjects at Bologna, and who added largely to anatomical knowledge, ventured to dispute or correct but few of the propositions of his predecessors in the study. To Vesalius belongs the credit of daring to expose the errors of the Galenian system. A Fleming by birth, he early migrated to Venetia, and lectured with immense success at Padua, and afterward at Bologna and Pisa. So prominently does his simple adherence to facts and disregard of tradition and prejudice, exhibit him as superior to the more servile workers in the science of medicine before his time, who were in reality mere commentators on Hippocrates and Galen, that he has been called the father of human anatomy. He elaborated a comprehensive system, which, although necessarily incomplete, contained few mistakes, and he exposed and corrected a vast number of errors, which, up to that time, had been received without question.

The beginning of the sixteenth century, when Luther nailed his ninety five propositions to the gates of Wittenberg, marked the commencement of a new era in science, as well as in religion. The spirit of Protestantism influenced the study of medicine, and Vesalius did not stand alone. Linacre, who had studied at Padua before the time of Vesalius, had just established the College of Physicians in London, thus emancipating medicine to a great extent from priestly influence. Hitherto the power of approving and licensing practitioners had been committed to the bishops in their several dioceses, and the practice of physic was accordingly engrossed by illiterate monks and other ignorant empirics, who, as the charter of the college expresses it, "boldly and accustomably took upon them great cures, to the high displeasure of God, the great infamy of the faculty, and the grievous hurt of his Majesty's liege people." Physicians had gradually become distinct from the sacerdotal order on the Continent, and as early as the beginning of the fourteenth century we find that monks were expelled from the hospitals by the University of Vienna for their "insatiate avidity, and flagrant incompetency," and the care of the sick poor given into the hands of the laity. The monks revenged themselves by procuring an order from the Pope, prohibiting physicians from visiting their patients a second time, without summoning a priest to attend also!

From the Protestant era, original investigation and the accumulation of facts from accurate observation proceeded with a rapidity and certainty beyond all previous experience. Their progress was, nevertheless, impeded, and the value of the results produced depreciated by several opposing influences.

The Romish Church, ever intolerant of novelties which did not emanate from herself, viewed with apprehension and hatred all scientific discoveries, since they were subversive of dogmas which infallibility had sanctioned and approved. Roger Bacon was persecuted by a priesthood said to be so ignorant that they knew no property of the circle, except that of keeping out the devil—and the cry of sorcery or heresy was raised against succeeding explorers of Nature to the time of Galileo. It is terrible to think how many great lights must have been extinguished, how many great discoveries nipped in the bud, by the rigorous stamping out of heresy and unholy pursuits, carried on by the Inquisition. And Protestantism, which had its origin in a similar spirit of inquiry, deprecated with almost equal bigotry, though with less power, every conclusion which seemed contrary to her own interpretation of the word of God. God had afflicted Job with horrible diseases, and the history of the demoniacs proved that devils could derange bodily functions; therefore to doubt these causes was to impugn the veracity of the Bible.

As late as the year 1699, the Royal Society was attacked by theologians soon after its foundation, on the ground that the society neglected the wiser and more discerning ancient philosophers, and depended too much on their own unassisted powers—that, by admitting men of all religions and all countries, they endangered the stability of the Established Church—and, more than all, that a philosophy, founded on experiment, was likely to lead to the overthrow of the Christian religion, and even to a formal denial of the existence of God. And about this time, the orthodox and devout Willis, who gave all his Sunday fees in charity, who procured a special early service daily at a church in St. Martin's Lane, in order that he might be able to attend before he visited his patients, and dedicated his treatise, "De Animâ Brutorum," to the Archbishop of Canterbury, was condemned by the theologians of the day as tainted with heresy, because he ventured on some speculations not sanctioned by the verdict of antiquity.

The Humoral Pathology had been established as a simple explanation of ordinary diseases, which the more educated people had begun to think might be owing to natural causes; but the pestilences which ravaged nations, and indeed any strange and unaccountable malady, were still unhesitatingly referred to some unpropitious conjunction of the planets, or the machinations of the devil. This Humoral Pathology assumed the existence of four humors in the body, viz., blood, melancholy, choler, and phlegm. Blood was supposed to be formed by the liver, melancholy by the spleen, choler by the gall bladder, and phlegm by the stomach. The temperament of each individual was termed sanguine, melancholy, choleric, or phlegmatic, according to the humor naturally predominant in his constitution, and one fluid prevailing with abnormal excess over the others gave rise to morbid conditions. The faculty still held to the doctrine of "signatures," as it was called, as the basis of therapeutics; which doctrine assumed certain remedies to be potent in certain diseases, because there was some external resemblance or fanciful connection between the two. Thus, scarlet bed curtains were a cure for scarlet fever, measles, or any disease with a red eruption on the skin, and the grandfather of Maria Theresa died of smallpox, wrapped, by order of his physicians, in twenty yards of scarlet broadcloth! The yellow powder turmeric was a remedy for jaundice, the lung of the long winded fox a cure for asthma and shortness of breath; the heart of a nightingale was prescribed for loss of memory; the royal touch was a specific for scrofula or king's evil; and we find John Brown, chirurgeon-in-ordinary to Charles II., writing a treatise on the "Royal Gift of Healing Strumæs by Imposition of Hands," with a description of the proper and efficacious manner of conducting the ceremony. This delusion actually held its ground until the eighteenth century, when the great Dr. Johnson was touched by Queen Anne.

As late as 1623, Sir Kenelm Digby, the Admirable Crichton of his time, produced a sympathetic powder which was to cure wounds even when the patient was out of sight. This powder had extraordinary success, and its efficacy was almost universally acknowledged.

The more advanced minds were, in truth, not yet in the condition most favorable to the development of the sciences. Men of the most daring and original minds were tainted with superstition and credulity. Luther believed that the devil tormented him with earache; he emphatically enforced the duty of burning witches, and earnestly recommended some anxious parents to destroy their son, whom he declared to be possessed by an evil spirit! The belief in witchcraft was still universal, and the last witch was not burnt until 1722. Bishops, judges, magistrates, and learned men, all agreed in crediting the reality of sorcery and the efficacy of astrology.

Men wasted their time and energies in discussing whether a spirit could live in a vacuum, and whether, in that case, the vacuum would be complete; and whether Adam and Eve, not being born in the natural manner, possessed the umbilical mark. They theorized concerning the nature or essence of vital principles and other mysterious entities, and heaped hypothesis on hypothesis, careless of their foundations. Van Helmont, who is immortalized by the discovery of the gases, adopted as an established fact a theory which he founded on the hypothetical "archæus" or entity of Paracelsus. The archæus being an immaterial force or spiritual agent, Van Helmont believed that each member of the body had its own particular archæus, subordinate to the central or principal archæus, which he localized in the stomach; and, as he found that nauseating medicines impaired mental vigor, he assigned to the stomach the seat of the intellect also. Thus, although he made great discoveries in chemistry, his physiology was wildly imaginary and unwarrantably assumptive, and detracts from the fame which his valuable researches in chemistry conferred upon him.

The matter of fact Vesalius, too, who had dared to fail in seeing the openings through the septum of the heart, which Galen had declared to exist, did not dream of disputing the theory of that authority concerning the distribution of the blood, which required that the blood from the two ventricles should intermingle, and therefore imagined that it distilled through the pores of the unbroken and impermeable partition; and, contrary to what seems to have been his general temper, he steadily denied the existence of valves in the veins, which had been observed by others, although he might have verified their statements had he been in this instance open to conviction. Servetus, also, the victim of Calvin, who burnt him and his works together at Geneva, when he had discovered the pulmonary circulation, and almost grasped the great secret afterward found out by Harvey—the complete circulation of the blood—instead of proceeding with the investigation, assumed all other errors except the one he had disproved, and describes how the air passes from the nose into the ventricles of the brain, and speculates how the devil takes the same route to the soul. The spirit of the age continued eminently unpractical, and men took interest in facts only as they could be bent to the support of preconceived theories, "spinning," as Lord Bacon says, "like the spider, the thread of speculative doctrine from within themselves," and regarding the perfection and symmetry of their production, rather than its truth and certainty.—Abstract from Fortnightly Review.